Imitation crab is one of the lowest-mercury seafood options available. The primary fish used to make it, Alaska pollock, has a mean mercury concentration of just 0.031 parts per million, placing it in the FDA’s “Best Choice” category for safe consumption.
What Imitation Crab Is Actually Made Of
Imitation crab is made from surimi, a processed fish paste. The main ingredient in most products is wild Alaska pollock, harvested from the Bering Sea and the Gulf of Alaska. Some brands also use Pacific whiting. Both are small, fast-growing cold-water fish that sit low on the food chain, which is exactly why they accumulate so little mercury. Larger, longer-lived predatory fish like swordfish and shark concentrate mercury over decades of eating smaller fish. Pollock simply doesn’t live long enough or eat high enough on the food chain for mercury to build up in meaningful amounts.
How Pollock Compares to Other Fish
The FDA tested 95 samples of pollock between 1991 and 2008. The average mercury level was 0.031 ppm, with some samples registering no detectable mercury at all. To put that in perspective, swordfish averages 0.995 ppm, roughly 32 times higher. Even canned light tuna, often considered a safe choice, averages about 0.126 ppm, four times higher than pollock.
Both pollock and whiting earn the FDA’s “Best Choice” designation, meaning you can safely eat two to three servings per week. That’s the highest safety tier the agency assigns.
Safety During Pregnancy
Because pollock falls into the “Best Choice” category, pregnant and breastfeeding women can eat up to two to three servings (8 to 12 ounces total) per week without concern about mercury exposure. This makes imitation crab a convenient option for getting some seafood into your diet during pregnancy, especially if you’re wary of higher-mercury fish. The mercury content is low enough that it’s functionally a non-issue at normal consumption levels.
Other Nutritional Considerations
While mercury isn’t a concern with imitation crab, there are a few other things worth knowing about the product. A 3-ounce serving contains about 81 calories and 6.5 grams of protein, which is less than half the protein you’d get from the same amount of real crab. It also contains roughly 12.8 grams of carbohydrates, mostly from starches and sugars added during processing. Real crab has zero carbs.
Sodium is another factor. A serving of imitation crab delivers about 450 mg of sodium, nearly 20% of the recommended daily limit of 2,300 mg. That adds up quickly if you’re eating it in sushi rolls or dipping it in soy sauce. People watching their salt intake should keep portion sizes in mind.
Imitation crab also contains added phosphates, which help with texture and moisture. For most people this is harmless, but those with kidney disease are typically advised to limit foods with added phosphates. On the plus side, a serving provides 35% of the daily value for selenium and 21% for vitamin B12, both important nutrients that come naturally from the pollock itself.
Imitation Crab vs. Real Crab for Mercury
If your main concern is mercury, both imitation and real crab are safe choices. Real crab species like king crab and snow crab also fall into the FDA’s low-mercury categories. The difference comes down to nutrition and processing. Real crab has more than double the protein, far more B12, and significantly more zinc and copper. Imitation crab is cheaper, more shelf-stable, and widely available in ready-to-eat forms. Neither one poses a mercury risk at normal consumption levels.